Effect of Planting Density on Yield and Main Agronomic Characters of Different Plant Type Maize Hybrids

Loose-type maize cv.Changyu 13,semi-compact maize cv.Dongdan 60 and compact maize cv.Zhengdan 958 were planted at 39 000 plants/ha,48 000 plants/ha and 57 000 plants/ha,respectively,to investigate the effects of planting density on the yield,ear and kernel traits and plant traits in maize hybrids of different plant types.The results showed that the yields of three maize cultivars increased with increasing planting density,and Dongdan 60 gave the highest yield.With the increase in planting density,kernels per row,ear length,ear diameter and cob diameter,ear leaf area and 1 000-kernel-weight decreased,but plant height,ear height and tassel branch number increased.The interactions between plant type and planting density were non-significant in the traits investigated.Therefore,it is the key for improving maize yield per unit area in Chongqing to choose elite maize cultivars as well as adopt a reasonable planting density.